[Panda-Man]

My 2009 e90 xdrive sedan was recently t-boned on the driver side in a hit and run. Both the drivers' side doors and front suspension was replaced. I got my car back the other day and noticed the trip range gauge was really off. I've attached a picture of it below.



Any ideas what could be wrong? Notice, I've only driven 5 miles but the miles to empty changed from 288 to 273, a 15 mile difference!

Thanks in advance.

[Sgop335]

Hope you are not kidding! anyways, miles to empty varies based on your gas mileage, so it can be different from your odo. You follow?

[Panda-Man]

Originally Posted by Sgop335

Hope you are not kidding! anyways, miles to empty varies based on your gas mileage, so it can be different from your odo. You follow?

I know, but I don't remember it varying that much? I don't step on the gas that hard! I recall miles to empty was pretty accurate and from my queries it's based on the last 18 miles driven.

[MuffinMan910]

I wouldn't really worry about a 15 mile difference. Also, could be the camera angle but your second picture looks like you used a lot of gas for 5 miles of driving

[VTECaddict]

It's going to change a lot depending on your recent MPG history for the last 18 miles. Go cruise on the highway at a steady 65mph for 20 min and it will shoot up to over 400mi.

[Wilt]

Originally Posted by Sgop335

Hope you are not kidding! anyways, miles to empty varies based on your gas mileage, so it can be different from your odo. You follow?

^

You have a nearly full tank of gas, so about 16 gallons. In driving 5 miles, your actual decrease in apparent mpg is not a loss of 15 miles on the tank, but really 10 miles lost to reduced efficiency. After all, you should have seen 288 decline to 283 left on tank, but it declined to 273.

• If you started with 17.7 mpg assumption it could go 283 miles on 16.0 gallons;
• yet if it dropped by -1.13% to 17.5 mpg actual, you could go 'only' 273 miles assuming 15.6 gallons remaining (after your 5 mile drive)

Give it a rest...your mpg dropped by -1.13%... I have seen it fall more sitting at a single cycle of the signal lights!

[jt335i]

I’ve seen that kind of variation in my car’s range read out. The range is calculated by your car’s internal computer by running an average consumption over a window of time and distance, and also by the amount of fuel in the tank. It does not go by the Ave consumption (MPG) read out on the “On Board Computer” in your iDrive. The car’s fuel injection system makes a fuel consumption calculation by counting the number and duration of pulses made by the fuel injectors as they squirt gasoline into the combustion chambers of the engine. Then, the onboard computer system’s fuel economy gauge divides the distance the car travels by this estimated fuel consumption calculation. So, for example, if you had recently been travelling on the highway before the accident, your range was calculated based on the highway MPG calculation of that last driving session. In the time between when you picked up your car from the repair shop and the 5 miles you drove it home, your car may been sitting idling for an extend period of time at the repair shop parking lot and in stop and go traffic on the way home.